Choose all the expressions $/$ programs that induce side effects.

Group of answer choices

$($define a $1)(($lambda $($x$)$ x$)$ a$)$

$(+($let $(($a $1))$ a$)2)$

$(($lambda $($x$)(+$ x $1))(($lambda $($x$)$ x$)1))$

$($deref $($ref $1))$

$($let $(($x $($ref $1)))$ x$))$